1. Field of the Invention
This invention relates to a sealing means for a rolling bearing for a strut-type suspension. More particularly, the present invention relates to a sealing means for a rolling bearing for a strut-type suspension in which a sealing member of a thrust ball member adapted to be assembled to a piston rod of a shock absorber, engages a radial inner end portion of a rotary bearing ring so as to be integral with the bearing.
2. Prior Art
Strut-type suspensions for a vehicle's wheel, are well known. One such typical construction is shown in FIG. 1 hereof. As shown in FIG. 1, a piston rod or strut shaft 10' of a shock absorber or strut has a stepped shoulder portion 11' upon which is placed the radial inner part of a holding case 38' of a stationary bearing ring 32'. Above the holding case 38' a radial inner part of both a lower plate 14' and an upper plate 13' of a shock absorbing rubber mount 12', as well as a washer 16' are stacked one after another. These stacked members are tightly fixed by a nut 17' coupled to the threaded neck portion of the piston rod 10'.
The shock absorbing rubber mount 12' is, ordinarily, a pre-fabricated sub-assembly consisting of the upper plate 13', the lower plate 14' and a rubber buffer 15'. The rubber buffer 15' is positioned between the upper plate 13' and the lower plate 14'. The rubber buffer 15' is integrally adhered, both to the upper plate 13' and to the lower plate 14', by vulcaniziang. The upper plate 13' is fixedly attached to a mounting plate (not shown) at the side of a vehicle body (not shown).
According to the prior art construction, a rotary bearing ring 35' of a small bearing 30' is disposed on an annular upper seat 18' for a coil spring 19' with a sealing member 40' being interposed therebetween.
The annular upper seat 18' is axially movable relative to the piston rod 10' together with an outer cylinder of the shock absorber (not shown) via the coil spring 19' which is coaxially disposed between a lower spring seat for the coil spring (not shown) and the upper coil spring seat 18', itself. The upper spring seat 18', also, can support a thrust load by the ball bearing 30' when it is rotated, together with the outer cylinder around the piston rod 10'.
Usually, the sealing member 40' comprises a core metal 42' and an elastic member 41', such as a rubber or the like, which are integrally attached by vulcanizing. A radial inner marginal lip 43' and a radial outer marginal lip 47' of the sealing member 40' are slidably contacted with the outer surface of the piston rod 10' and the outer surface of the holding case 38', respectively. This construction prevents any foreign material from entering into the interior of the ball bearing 30'. At the same time, the sealing member 40', also, functions to prevent any leakage of the lubricant applied to the ball bearing 30' either when the coil spring seat 18' moves axially or when it is rotated around the piston rod 10'.
Generally, such prior art sealing means for a bearing for a strut-type suspension are characterized as having a construction comprising lips which are provided at the radial inner part and the outer part of the rolling bearing.
However, since such conventional sealing means are separated ones, in which the sealing member is disposed as a discrete member from the bearing, there are found various drawbacks, such as not only inconvenience in handling and storage but, also, require complicated assembly procedures.